Typically, a video teleconference session using two-way communication of images and voice is carried out among a plurality of groups with the use of a plurality of conference devices each equipped with a camera, a microphone, and a speaker.
In such a video teleconference device, the voice or sound from one group is received as input by the microphone of the corresponding conference device and is sent to the teleconference device of other group via Internet (communication network). At the other group, the voice or sound is output from the corresponding speaker. Similarly, the voice or sound from the other group is received as input by the microphone of the corresponding conference device and is sent to the teleconference device of the one group via Internet. At the one group, the voice or sound is output from the corresponding speaker (for example, see Japanese Patent Application Laid-open No. 2002-262250 and Japanese Patent Application Laid-open No. 2006-138972).
However, there is a risk that the voice or sound of the one group that is output from the speaker of the other conference device is again received as input by the microphone of the other conference device, and eventually gets output from the speaker of the one group. Similarly, there is a risk that the voice or sound of the other group that is output from the speaker of the one conference device is again received as input by the microphone of the one conference device, and eventually gets output from the speaker of the other group. That is, there is a risk that the echo effect or the howling effect occurs.
The present invention is made in view of the aforementioned issue and it is an object of the present invention to provide a conference device in which the echo effect or the howling effect can be effectively curbed with a simple configuration.